Telephonograph.



E. CHABEAULT.

TELEPHONOGRAPH.

APPLICATION FILED FEB. 10, 1913.

3 SHEETS-SHEET 1.

flveniar E. CHABEAULT.

TELEPHONOGRAPH. APPLICATION FILED FEB. 10, 19l3.

Ru 1 9 1 00 1 P p A d e t n Du 0 a P Lz/enz'or E. CHABEAULT.

TELEPHONOGRAPH. APPLICATION FILED FEB.10,1913.

Patented Apr. 13, 1915.

L, 1 5 5am 1.11 0

3 SHEETS-SHEET 3.

Iwz/ntor,

fima't @fajewlt EMILE CHABEAULT, 0F MARSEJELLE, FRANCE.

anse.

To all whom it may concern Be it known that l, EMILE ,CHABEAULT, a citizen of the French Republic, residing at 65 Rue cle lAbb-de-IEpe, Marseille, lBouches-du-Rhone, France, have invented a new and useful Improved Telephonograph, of which the following is a specification.

This invention relates to an apparatus called a .telephonograph, and the "purpose of said apparatus is first to collect sonorous vibrations as a spy telephone would do and to obtain by a microphonic action an undulating current of as great magnitude as is desired; second to operate by this undulating current directly or through the secondary of an inductioncoil a receiver, the diaphragm of which under the action of these powerful vibrations is thrown into powerful mechanical movement so that the receiver acts as a loud speaking tele hone and the vibrations thus obtained can e recorded.

v i The features of the apparatus forming the subject of the present invention comprise in the first place the combination of the dif ferent devices and means for collecting sounds (microphoniclisteners) and for amplifying them and transmitting them to a special receiver acting as a loud speaking instrument. This receiver can moreover serve to record the sounds transmitted either by engraving on wax or in continuous and unlimited fashion by heliographic' action. In this last method, use is made of a roll of film which by suitable treatment may I furnish one or more phonographic records.

ltd

The features of the apparatus relate also to the arrangement, construction and actua tion of the principal devices, such asthe parts for collecting sounds (microphones or groups of microphones) indicated by the term listener induction coils or self inductance coils-as well as receivers (reproducers) the purpose being to proportion the magnitude of the electromagnetic masses to the increase in available energy in the undulating current. I r v Uther devices and advantageous arran ements will be disclosed in the following escription, in-particular the arrangement by Y which several listeners can be arranged about one stage, each intended to. act uponva separate reproducer so as to give an audience an aural impression of the movement of the actors.

' lln the drawings, Figures l and 1 are dia- Specification of Letters ilPatentr 3' are elevation and plan partially in section of a listener. Fig. 4 is an axial section of a double microphone. Fig. 5 is a vertical section to a larger scale. of a listener, the microphone-carrying, plates of which are mounted I Patented Apr. .13, 1915. Application flle'dl February 10, 1913. Serial No. 747,423.

between springs. Fig. 6 is a detail of a coil. 1

Fig. 7 is a vertical section of a reproducer.

Fig. 8 shows the diaphragm of the repro-' ducer carrying a sapphire for making a direct phonographic record. Fig. 9 shows the diaphragmof the reproduocr for-recording heliographically. The telephonographic apparatus of Fig. 1 comprises the devices necessary for collecting, reproducing and recording sounds. (a) The devices for collecting the sounds are the battery 1, they group or groups of microphones 2 and the induction coil 3. (b) To reproduce the sounds all that is necessary is to operate a receiver 4;

by means. of the microphone current, directly, or'better through the medium of the induction coil secondary, this, latter preferable arrangement being that's-hown in the drawing. (0) For recording all that is necessary is to cause the vibrating diaphragm of the receiver to actuate either an engraving stylus of the ordinary construction or a light screen 5 pierced with a hole to guide a ray of light from a luminous source 6 upon a sensitive roll of film 7 unrolled in front of it, the said band thus acted upon carrying a fine sinuous trace which represents the movements of the diaphragm. This film may be used to produce 'phonograms in the manner hereinafter explained.

The various devices which form the telephonographic apparatus have been designed arranged in a plane at right angles to the direction of propagation will be the more alike, for a given distance between the 'diaphragms the farther the diaphragms are from the sonorous source on account of the spherical form of the waves. On the other hand it is useless to extend the microphones very far in 'thedirection of propagation; If the microphones are 33 cm.

apart the one will be in the node of a vibra tion while the other will be in the loop,

and therefore while one is receiving useful vibrations the other will at that instant be mute. If the microphones are 66 cm. apart both will be affected by the loops of .vibra-.

tions. In this condition the vibrations acting on the microphones are not simultaneous and the two actions cannot be compoundedinto a single result. Therefore it 1s desirable to combine into as restricted a space as possible all the vibrating surfaces that it is desired to use. .To satisfy his condition the listeners are formed (Fig 2 and 3') by a wooden frame 8 within which are placed partitions 9 between which are free'spaces which permit the passage of the waves. The microphones 2 are dispose'd'along these partitions in such fashion as to occup as large an extent of their surface as possible. The partitions 9 terminate on the side from which the sound is coming in beveled edges 9 (Fig. With'the same'idea in mind of arranging as many microphones as possible ina given space, the air spaces between the plates carrying the microphones are reduced say to 5 mm. andthe thickness of the plates is also reduced to.a minimum by the arrangement adopted for mounting the microphones. The plates are formed of three thicknesses, two equal thicknesses. 9 (Fig. 4) and a much thinner portion 9 for example of 2 o'r 3. mm.', all't e, thicknesses being'of insulating material (wood fiber or molded-insulating material) and connected together by bolts such as 9. The plates 9 are pierced with holes in which are lodged the microphones 2. A threaded ring "l0 forms a sort of box upon which screws the flange 11 which serves to keepthe vibrating diaphragms 2 in place.

one plate." The total thickness-of the plate is about 25 mm. These arrangements enable the surface occupied by a 'ven number of microphones to be cpnsi erably reduced. The plates might also caffy two microphones in their depth. But. the positions they would have would be disadvantageous inasmuch as it would be'impossible'for them to be subject to the same effect at the same instant; in spite of this defect the arrangement may be acceptable for powerful sounds.

.If it is desired to avoid such inversion the plates 9 carrying the microphones 2 can be mounted between the two springs 18, 17

'(Fig. 5), the plates carrying at the top anabutment 18 of wood orhard rubber. A solenoid 19 is arranged on the frame and its movable magnetic core 20 is suspended by a spring 21 in the line of the abutment. If a pulsating current asses through the solenoid the core is pulled down. Each time it is pulled down it strikes the abutment and gives the plate a sufiicient jar to lessen or estroy the effects of settling. The microphones are all arranged in series and the -'variable resistance obtained is the sum of all the variable resistances of each microphone. Hence the necessity .if n- 'microphones are employed of multiplying the re sistance of-the coils by n.

002'Z3.On the other handasthe value of the intensity varies within thesame limits as for one microphone the cross section required for the coils is the same as in the. case of a single microphone. This reasoningapplies as Well to extra-current coils as to the primary of the induction coils and to the windings of the reproducers. The extent of the winding and its volume and inconsequence, its weight, requireto be multiplied 3y the number 'of microphones employed.

his multiplication is effected by increasing one factor of the volume or of the weight,

viz. the length. The cross section of the iron and the thickness. of the coil remain constant. If the length of the coil is I for one microphone, for n microphones it will be n.

(Fig. 6). To facilitate the construction, as the ength may attain a considerable value, elementary COllS made for four or five micro bones are grouped in series. The secon ary 3 of the induction coil 3 will occupy n times the volumeof the'secondar'y for a coil for one microphone and its resistance will be chosen with reference to the length of the line.

Reproducra-As the undulating current obtained has a power proportioned to the number of microphones in order to utilize it to tliebest advantageit is necessary to construct reproducers specially for it and to increase the extent of the magnetic field. For this urpose the number of poles acting on the vi rating diaphragm 22 is increased men-tee box 4* and in this is mounted the vibrating i lend themselves best to the disposition of diaphragm 22; a spring 27 presses the cores toward the diaphragm and they are held back by a threaded pin 28 with a nut 29 for adjustment. The bar magnets may advantageously be replaced by electromagnets. There may be any desired number of poles but the numbers seven and nineteen seem to the coils. The poles are made opposite in sign in order to reduce the reluctance of the magnetic circuit of the reproducer. The coils are so connected as to produce opposite poles. The reproducer carries a trumpet 30.

if it is intended to reproduce as a loud speaking instrument. if it is used for recording, the diaphragm 22 actuates an arm 31 (Fig. 8) through a pin 32 kept to its work by a spring 33. The arm 31 is hinged on a pointed axle on a'crossbar secured to the box of the reproducer 4; at the end of the arm 31.there is a sapphire 34 for engraving on the wax (Fig. 8) or the arm may be prolonged and end in a screen for recording photographically (Fig.

fiecorde'ra -The screen 5 is pierced at its center with a very small pinhole. A luminous ray passing throughthis hole will make an impression von the sensitized surface of a roll of film upon which it will leave a fine sinuous trace which will represent the. movements of the diaphragm. As the work of engraving is obviated the line obtainedrwill be very exact. This film 7 is unrolled at uniform speed in front of the perforated paper screen of the reproducer. When developed. and fixed the film forms a block from which impressions may be made on a band of .bichromated gelatin su ported on a film of celluloid. This band when developed by the aid of warm water and dried will have a'sinuous line in relief. 1 It passed through a rolling mill a ainst a sheet of lead it will give a meta ic' intaglio co y. Thelead'plate is woundhelically aroun a drum which serves to support it. By a al vane-plastic process it is covered with a ed of nickel or copper. y this means a metal- 110 band is obtained engraved in relief. If this metallic band is passed through a rolling mill with a band of celluloid in contact with its engraved surface it will produce a flexible copy engraved in intaglio. The rolling mill should be warmed to make this celluloid capable of receiving the im rint. The engraved band thus obtained, i unrolled uniformly, will enable a phonographic diaphragm provided with a stylus to reproduce the recorded sounds. The celluloid may be replaced by, any other material which can take the membrane and remain comparatively flexible without risk of destruction.

Multipze recarols.-Tt is conceivable that several traces may be recorded simultaneously on a single roll of film by placing several reprodu'cers side by side, each reproducer being connected to a distinct listener. It is thus possible to give an audience an aural im ression of the movement of the actors. 11 that is necessary is to, arrange the difierent listeners in difierent places on the actual stage. Taking the most simple case of two listeners, one on the right of the sta e and the other on the left 5 the record wil have two lines. When, for instance, the

actors pass from right to left the right hand listeners will have a decreasing record while the left hand will increase. Tn the reproduction the phonographic diaphra cor- -.responding to the right hand line Wlll readily reproduce this weakenin of the sound,

while the left hand one wil reproduce the corresponding intensification recorded' by the corresponding listener. The audience will thus have the impression that they .would have before the stage itself, viz. of

the actors moving.

Whatlclaim is: p Y I A listening device for telephonographic apparatus, consisting in a box open upon one side, a series of partitions arranged partot.

allel in said box, all having one edge. to-

ward the open side of said box, spring'cushions between the walls of said box and said partitions, and automatic means for setting each partition in vibration independently.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

EMILE CHABEAULT. Witnesses: v

OAzAux, I. Mower. 

